as far as nutrition, calorieking.com has pretty much anything you can eat on it.for Spirulina

1 cup dried (1/2 oz)44 calories1.2 g Fat3.6 g Carb8.6 g protein

so 1 cup dried powder has about the same protein as 1 cup of milk or 1/5 cup uncooked black beans. but i would highly discourage eating 1 cup of dry powder.It is proportionally high in protein (about 50-70% of calories) but i don't think it could realistically be a significant source of protein in your diet.

It is full of other nutrients, and is great for you. But i suggest you look elsewhere for the major sources of your protein.

as a protein source ,it is not so rich. the richest vegetal protein source is soy. it is the nearest one to meat. but spiriluna is an fe(iron) source. spiriluna is vegetable fibre so it boosts and regularizes intestinal activity. it prevents contipation, sweeps the intestines which is a good way of colon canser prevention. as a vegetal fibre ,it lowers glisemic index of the foods, it is good for fight against insulin resistance,metabolic syndrome,impaired glucose tolarance,prediabetes. this is good for fat loss.